Table 5.

Decision tree–based configuration of feature contributions.

Top feature configurationsa		Number of cases in the node, n	Dominant outcome	Percentage of dominant cases, n (%)
Subgroup 1: These configurations suggest a simple type of follow-up service resulting from previous offline diagnoses
	Offline AND low total dialog (≤11.5)	850,338	Free	819,363 (96.36)
	Offline AND low total dialog (≤11.5) AND low response rate (≤0.35)	743,165	Free	735,571 (98.98)
Subgroup 2: This configuration suggests a complex service extension from the previous offline diagnoses, which requires intensive patient-provider interaction.
	Offline AND high total dialog (≤11.5) AND high response rate (>0.25)	99,355	Paid	99,355 (100)
Subgroup 3: These configurations suggest the patient has no offline connection with the physician but is paying a premium for the online consultation rather than using a social return to show gratitude.
	Nonoffline AND no social return	335,047	Paid	281,247 (83.94)
	Nonoffline AND no social return AND nonprivate	248,294	Paid	242,265 (97.57)
Subgroup 4: This configuration suggests the patient has no offline connection with the physician, has a less intensive online consultation experience, and offers a social return as compensation instead of payment.
	Nonoffline AND social return AND low total dialog (≤10.5)	80,804	Free	73,839 (91.38)
Subgroup 5: This configuration suggests the patient has no offline connection with the physician and engages in an intensive online interaction, providing both payment and a social return as compensation.
	Nonoffline AND social return AND high total dialog (>10.5)	36,152	Paid	25,899 (71.64)

^aFor each tree split, if no dominant outcome emerges (ie, free cases <80% or paid cases <70% at the focal split), we do not consider it as an important subgroup because additional service features are required to better classify these cases.